Electronic devices, such as integrated circuit (IC) packages, typically include a plurality of semiconductor devices arranged on a carrier and encapsulated. Prior to encapsulation, bond wires are attached to bond pads on the semiconductor devices and to lead fingers on the carrier. The device is then encapsulated to protect the device and form a housing from which the leads extend.
Transfer molding is one known technique for encapsulation of electronic devices. This includes transferring a thermally liquefied molding material under pressure into a preformed cavity. However, the mold material used in transfer molding processes typically is pre-cured to obtain a solid material, then ground and palletized. This can result in flowability problems. Moreover, transferring the molding material under pressure can result in damage to components of the device, especially the delicate bond wires.
Compression molding is another encapsulation method, wherein a liquid molding material is dispensed on the device to be encapsulated and the device is compressed between molds to spread the mold material over the device. With some configurations of semiconductor devices on the carrier, it can be difficult to get the molding material to flow to all areas of the device, resulting in undesirable voids in the encapsulated product.